<?php

declare(strict_types=1);

/*
 * This file is part of PHP CS Fixer.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace PhpCsFixer\Fixer\Basic;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\FixerDefinition\CodeSample;
use PhpCsFixer\FixerDefinition\FixerDefinition;
use PhpCsFixer\FixerDefinition\FixerDefinitionInterface;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;

final class SingleLineEmptyBodyFixer extends AbstractFixer
{
    public function getDefinition(): FixerDefinitionInterface
    {
        return new FixerDefinition(
            'Empty body of class, interface, trait, enum or function must be abbreviated as `{}` and placed on the same line as the previous symbol, separated by a single space.',
            [new CodeSample('<?php function foo(
    int $x
)
{
}
')],
        );
    }

    /**
     * {@inheritdoc}
     *
     * Must run after BracesPositionFixer, ClassDefinitionFixer, CurlyBracesPositionFixer, NoUselessReturnFixer.
     */
    public function getPriority(): int
    {
        return -19;
    }

    public function isCandidate(Tokens $tokens): bool
    {
        if (\defined('T_ENUM') && $tokens->isTokenKindFound(T_ENUM)) { // @TODO: drop condition when PHP 8.1+ is required
            return true;
        }

        return $tokens->isAnyTokenKindsFound([T_INTERFACE, T_CLASS, T_FUNCTION, T_TRAIT]);
    }

    protected function applyFix(\SplFileInfo $file, Tokens $tokens): void
    {
        for ($index = $tokens->count() - 1; $index > 0; --$index) {
            if (!$tokens[$index]->isGivenKind([...Token::getClassyTokenKinds(), T_FUNCTION])) {
                continue;
            }

            $openBraceIndex = $tokens->getNextTokenOfKind($index, ['{', ';']);
            if (!$tokens[$openBraceIndex]->equals('{')) {
                continue;
            }

            $closeBraceIndex = $tokens->getNextNonWhitespace($openBraceIndex);
            if (!$tokens[$closeBraceIndex]->equals('}')) {
                continue;
            }

            $tokens->ensureWhitespaceAtIndex($openBraceIndex + 1, 0, '');

            $beforeOpenBraceIndex = $tokens->getPrevNonWhitespace($openBraceIndex);
            if (!$tokens[$beforeOpenBraceIndex]->isGivenKind([T_COMMENT, T_DOC_COMMENT])) {
                $tokens->ensureWhitespaceAtIndex($openBraceIndex - 1, 1, ' ');
            }
        }
    }
}